Collateral circulation in the posterior fossa via leptomeningeal anastomoses.
D001099:Arachnoid / Q000098:blood supply*; D001488:Basilar Artery / Q000503:physiopathology*; D002533:Cerebral Angiography; D002560:Cerebrovascular Circulation / Q000502:physiology*; D003097:Collateral Circulation; D006801:Humans; D002542:Intracranial Embolism and Thrombosis; D008297:Male; D008875:Middle Aged; D010841:Pia Mater / Q000098:blood supply*; D013382:Subtraction Technique